BRIDGEPORT, Conn. – The commuter train derailment and collision that left dozens injured outside New York City was not the result of foul play, officials said Saturday, but a fractured section of rail is being studied to determine if it is connected to the accident.

National Transportation Safety Board member Earl Weener said Saturday the broken rail is of substantial interest to investigators and a portion of the track will be sent to a lab for analysis.

Weener said it’s not clear if the accident caused the fracture or if the rail was broken before the crash.

He said he won’t speculate on the cause of the derailment and emphasized the investigation was in its early stages.

Seventy-two people were sent to the hospital Friday evening after a Metro-North train heading east from New York City derailed and was hit by a train heading west from New Haven. Most have been discharged.

Officials earlier described devastating damage and said it was fortunate no one was killed.

“All of the injured people described the really harrowing experience of having the train jolt to a stop, the dust, darkness, other kinds of factors that made it particularly frightening,” said U.S. Sen. Richard Blumenthal, who visited several patients in the hospital.

Blumenthal said a Metro-North conductor helped passengers despite her own injuries.

“Her story is really one of great strength and courage helping other passengers off the train in spite of her own very severe pain,” Blumenthal said. “She eventually had to be helped off herself.”

The crash damaged the tracks and threatened to snarl travel in the Northeast Corridor. The crash also caused Amtrak to suspend service between New York and Boston.

“The damage is absolutely staggering,” Blumenthal said, describing the shattered interior of cars and tons of metal tossed around. “I feel that we are fortunate that even more injuries were not the result of this very tragic and unfortunate accident.”

U.S. Sen. Chris Murphy said it was “frankly amazing” people weren’t killed.

Both said new Metro-North Railroad cars built with higher standards may have saved lives.

Metro-North said train service will remain suspended between South Norwalk and New Haven until further notice.

Railroad officials said rebuilding the two tracks and restoring train service “will take well into next week.”

NTSB investigators arrived Saturday and are expected to be on site for seven to 10 days. They will look at the brakes and performance of the trains, the condition of the tracks, crew performance and train signal information, among other things.

When the NTSB has concluded the on-site phase of its investigation, Metro-North will begin to remove the damaged rail cars and remaining debris.

The process of removal requires specialized, heavy equipment that will be in place today, officials said.

Only after the damaged train cars have been removed can Metro-North begin the work of rebuilding the damaged tracks and overhead wires.